Another Backfill question!!!

[SunnyP2000]

Hello all, close to getting an inground steel lined vinyl Pool. My Pool builder insists on using excavated dirt to backfill which I don't want to use. he says he does pillars out of cinderblock (please see pic) every 5 feet all around the pool so when mason does concrete or pavers its "super strong" around the pool . he says he has been doing it for long time and never had sinking issue. To do the cinderblocks its a $500 up charge. should I tell him not to do cinderblocks and just ask for #57 gravel backfill ? also I am doing water fall wall( please see pic) one of the side . I am assuming that's quite a bit of weight on that that side. maybe @jimmythegreek can chime in. I just don't want any sinking issues.

 

[jimmythegreek]

I've never seen such a thing. On a concrete deck ita easier to just add deck supports to the frame order. for extra support use 4" PVC drain pipe when you pour the collar amd fill them to top of wall height all around the pool. Where the waterfall goes you want them closer and even a slab on top umder paver height if you do pavers. Theres no way I would use excavated dirt under pavers here even if owner signed a no fix clause, it will settle guaranteed. Maybe where you are the dirt is sandy gravel oceanside type material, that could be used if it passes proctor density on packing it. The cinderblock thing doeant make much sense to me tho

 

[SunnyP2000]

I've never seen such a thing. On a concrete deck ita easier to just add deck supports to the frame order. for extra support use 4" PVC drain pipe when you pour the collar amd fill them to top of wall height all around the pool. Where the waterfall goes you want them closer and even a slab on top umder paver height if you do pavers. Theres no way I would use excavated dirt under pavers here even if owner signed a no fix clause, it will settle guaranteed. Maybe where you are the dirt is sandy gravel oceanside type material, that could be used if it passes proctor density on packing it. The cinderblock thing doeant make much sense to me tho

sorry @jimmythegreek i am trying to understand what's the best way to do this . i am no way near water but i think i do have very sandy soil. in addition to waterfall wall i am also doing 500sq paver patio. btw the pics are from another pool that he built , mine starts in two weeks . he is saying he makes a column out of cinderblocks which are height of the pool wall and then they are filled with concrete. this is done all around the pool every 5ft. then mason will do base layer then coping and paver patio. should i just tell him not to do this cinderblock wall and just fill with #57 gravel instead? what would you do if you were building this pool?

 

[jimmythegreek]

Piers work for helping concrete decks, they dont do anything for pavers. My soils are clay rich I could never use dirt only clean stone. I also usually need drainage on top of collar as the stone attracts moisture so a quick drain setup amd I backfill with all clean stone. I wrap the top of my stone with filter fabric amd start my 12" +/- of road base for pavers. I use geotextile under all my base materials. When I get near the top compacting in lifts I make forma for a pour for coping to sit on, then finish coping amd final base screed for pavers. Add sand, screed, lay pavers. Never gonna move my warranty is toilet paper

 

[SunnyP2000]

Piers work for helping concrete decks, they dont do anything for pavers. My soils are clay rich I could never use dirt only clean stone. I also usually need drainage on top of collar as the stone attracts moisture so a quick drain setup amd I backfill with all clean stone. I wrap the top of my stone with filter fabric amd start my 12" +/- of road base for pavers. I use geotextile under all my base materials. When I get near the top compacting in lifts I make forma for a pour for coping to sit on, then finish coping amd final base screed for pavers. Add sand, screed, lay pavers. Never gonna move my warranty is toilet paper

thank you so much i will insist on having backfill with clean gravel. what kind of drain setup do you recommend?

 

[jimmythegreek]

Perforated 4" ridgid to either daylight or a sump pit in a convenient location. The pit surrounded by clean gravel and fabric

 

[SunnyP2000]

Perforated 4" ridgid to either daylight or a sump pit in a convenient location. The pit surrounded by clean gravel and fabric

thank you

 

[jimmythegreek]

Btw if using a sump pit 10" is the minimum standpipe 12 is good. Just get a few feet of the black PVC ribbed and drill a ton of holes. Dump the 4" pvc into that after drilling the 4" holes where you need them. A paddle bit amd jigsaw will make the hole in a pinch. I leave long amd cut when finished height is there, then cap it

 

[SunnyP2000]

Btw if using a sump pit 10" is the minimum standpipe 12 is good. Just get a few feet of the black PVC ribbed and drill a ton of holes. Dump the 4" pvc into that after drilling the 4" holes where you need them. A paddle bit amd jigsaw will make the hole in a pinch. I leave long amd cut when finished height is there, then cap it

thank you planning on doing sump pit.